Had the idea a few days ago and have been thinking about it for a while but want to bounce it off you guys so I can maybe develop it a bit, or tell if there's something too close to it already out there.

The main premise is its a car salesman, kinda your classic sleazy, cheap suit, "Alright look, I can give ya a very good deal here.", guy. However, he isn't really tied to a specific dealership, he bounces from dealer to dealer, every week or so, and only operating a day at a time, and he has the ability to overpower someone's will, so he could convince you to buy a car, or maybe not shoot at him. Once an individual purchases a car from him, they immediately stop all connection with family/ friends, and within the next 48 hours, they will have driven the purchased car into or off of something that will result in a fatal car accident. The only way to prevent their death is to detain the affected individual for longer than the 48 hours, where they will have no memory of the past two days and consequently be very confused.

My main problem with the idea right now is that I think this guy should have an agenda and not just killing to take money or just for fun. Also, I think that he should be aware of the foundation to some extent.

All criticism is helpful, so if you have any ideas or want to point out that there are like 3 already created Scp's that are exactly the same, please do.

At the moment, it's just a thing that kills people - sure, there's a bit more of a backstory than just being a random object but, at its very heart, it is a thing that kills people, and that's just not interesting. Death is a cheap thrill that won't keep your reader invested, no matter what the presentation is - you need to develop a stronger narrative, which I think you are already aware of to an extent.

Why do people have to die? What's the purpose? Why do they stop connection with family/friends? If it's only over the course of 48 hours, are many people going to notice that a connection has stopped? I mean, if I didn't talk to anyone in any way - online or offline - for 48 hours, that wouldn't worry people I know, and I know many people in a similar situation. The sort of people who may have to buy a cheap car from a sleazy guy are probably adults who live alone, maybe not even in the same town as their folks, and maybe not seeing people they consider friends apart from at the weekend, for example. So how would this particular symptom be known in everyone? Why does it happen anyway, as I mentioned before?

Its core is the major problem. It's a thing that kills. That's been overdone here, at this point. You're trying to develop a narrative, but you're building it on a shaky foundation.

To add to this, maybe instead of crashing they just never stop driving and the car never runs out of gas? Or maybe every car that he sells breaks down at terribly inconvenient moments? For example, someone needs to go to the hospital and the car won't start.